Which version of Windows are you using?
It just means the display settings you are using are not compatible with your monitor..
If a PC restart doesnt fix, go into Safe mode (F8 at start up) (Earlier versions of Windows may have a VGA mode)

It's XP Home. I added an extra stick of RAM (which stopped the beeps), but then had this problem straight away. I'm in the library ATM so will try your advice when I get home. At what point exactly do I press F8?

first thing, remove the stick of memory. if you've changed the resolution to one that is too high for the monitor you get a message like that. reseat graphics card and reinstall drivers if it persists.

Daily Mail readers are living in a perpetual hell, expecting their homes to be overrun at any minute by hoodie wearing, skunk smoking, muslim, transgender, asylum seekers.

If the machine boots up to the POST screen and you can see what's on the display, and it only goes bad when Windows has booted up, it's possible the video card or monitor driver file has become corrupted and is defaulting to a very high or low scan rate. I'd reccommend that you load Windows into Safe Mode if you can and then try and uninstall both the video and monitor driver and then reboot the machine.

It could be that your machine is incompatible with the new ram, which has caused a problem on bootup, meaning the driver or driver references have become damaged.

first rule: if you make a change and get an error, reverse the change. using F8 + safe mode is usfull for s/w diagnostics, but if you just work around a problem it will come come back to bite you. identify and resolve the root cause.

If I remove the RAM I will just get the beeps again. Windows has been taking too much space as virtual memory.

maybe i missed another thread, but what beeps? (how many, you can tell the fault from them if you look it up). why did you increase the memory in the fist place? what memory do you have before/after the addition of memory? what else have you changed recently?

Last edited by beorhthelm; 03-03-2010 at 22:50.

Daily Mail readers are living in a perpetual hell, expecting their homes to be overrun at any minute by hoodie wearing, skunk smoking, muslim, transgender, asylum seekers.

A year or two ago after several months of the “windows is increasing your virtual memory” messages the pc wouldn’t start up at all. The diagnostic beeps emanating from it was a one second beep followed by a three second silence, repeating indefinitely. It’s a Cybercom Medion model PC MT5, type MED MT 132 with an AMD Duron processor.
I replaced the miserly 256 Mb of RAM with a 1Gb stick which immediately cured the problem. So, when the exact same thing happened again, I added back the original stick of RAM to give a total of 1ľ Gb. I then got the monitor problem, however now when trying to start it up again, I find I am just getting those beeps again, with nothing on the monitor. I have checked that both sticks are firmly seated.